othy: you know the trick of winning all hearts."

"No, I don't," said Dorothy earnestly. "If I really can do it, Ozma, I
am sure I don't know how I do it."

It took them a good two hours to reach the foot of the round, flat
mountain, and then they found the sides so steep that they were like
the wall of a house.

"Even my purple kitten couldn't climb 'em," remarked Dorothy, gazing
upward.

"But there is some way for the Flatheads to get down and up again,"
declared Ozma; "otherwise they couldn't make war with the Skeezers, or
even meet them and quarrel with them."

"That's so, Ozma. Let's walk around a ways; perhaps we'll find a ladder
or something."

They walked quite a distance, for it was a big mountain, and as they
circled around it and came to the side that faced the palm trees, they
suddenly discovered an entrance way cut out of the rock wall. This
entrance was arched overhead and not very deep because it merely led to
a short flight of stone stairs.

"Oh, we've found a way to the top at last," announced Ozma, and the two
girls turned and walked straight toward the entrance. Suddenly they
bumped against something and stood still, unable to proceed farther.

"Dear me!" exclaimed Dorothy, rubbing her nose, which had struck
something hard, although she could not see what it was; "this isn't as
easy as it looks. What has stopped us, Ozma? Is it magic of some sort?"

Ozma was feeling around, her bands outstretched before her.

"Yes, dear, it is magic," she replied. "The Flatheads had to have a way
from their mountain top from the plain below, but to prevent enemies
from rushing up the stairs to conquer them, they have built, at a small
distance before the entrance a wall of solid stone, the stones being
held in place by cement, and then they made the wall invisible."

"I wonder why they did that?" mused Dorothy. "A wall would keep folks
out anyhow, whether it could be seen or not, so there wasn't any use
making it invisible. Seems to me it would have been better to have left
it solid, for then no one would have seen the entrance behind it. Now
anybody can see the entrance, as we did. And prob'bly anybody that
tries to go up the stairs gets bumped, as we did."

Ozma made no reply at once. Her face was grave and thoughtful.

"I think I know the reason for making the wall invisible," she said
after a while. "The Flatheads use the stairs for coming down and going
up. If there was a solid stone wall to keep t